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Ask Keith Urbain, Operations Manager

We have experienced metals and plastics technicians who work with these materials every day, ready to help you. Send Keith your question and get your answer within a day. Email Keith here or send a text message.

"What is the difference between seamless and structural tubing?"

Extruded Structural Tube: This tube is produced by pushing metal through a die with tremendous force at elevated temperatures. The tube is actually "split" during the process and formed back together with high temperatures, pressure and a metallurgical weld that is inherent to the process. There is a slightly visible seam that may be noticeable to the naked eye if the tube is anodized or "finished." Although there is no difference in the chemical properties of the tube when compared to other tubes produced from the same alloy, it will not be guaranteed to transport liquid or gas with extreme pressure.Typical Alloys include 6061, other alloys available

Extruded Seamless Tube: Extruded Seamless Tube is produced by pushing a hollow billet through a die with tremendous force at elevated temperatures. This tube will not have a metallurgical weld or seam and is typically used for transporting gas, liquid, or other substances that involve pressure. The absence of a seam with this tube makes it ideal for anodizing and other finishing procedures.Typical Alloys include 6061, other alloys available

Drawn Structural Tube: A drawn structural tube starts out with the same processing as the extruded structural tube. However, the difference is this tube will be brought to its final dimensions by "cold drawing" or "cold working" the product through an additional die. These tubes have tighter tolerances on the O.D., I.D., and Wall thickness. In general, these tubes consist of smaller diameters and thinner wall thicknesses.Typical Alloys include 6063, 3003, other alloys available

Drawn Seamless Tube: A drawn seamless tube is produced in the same fashion as the extruded seamless tube. This tubing is then "cold drawn" or "cold worked" through an additional die to bring the product to its final dimensions. This type of tubing is generally used for transporting liquid, gas, or other substances that involve pressure. This tube would also be ideal for anodizing and other "finishing" procedures.Typical Alloys include 6061, 3003, other alloys available

"I'm cutting multiple lots of aluminum extrusions and stock shapes.What's the best way to avoid tool marks and ragged edges?"

Use a carbide tipped blade, such as Tenryu's Alumi-Cut or Industrial Series.

Also, it's always a good idea to lubricate when you're cutting any metal. Lubing will dramatically increase the life of the blade and give you cleaner, smoother, quieter cuts. At Schupan, we use an automatic lubing system that sprays a non-petroleum lube. Obviously, that's the best method. But if you're not operating at that level, you should still lubricate your blade. What can you use and where can you get it? The most common blade lube for lighter use is a wax stick, such as this one from Rockler.

Or, if you have a Home Depot near you, you may be able to find a similar stick from Oldham. In a pinch, you can use a shot of WD-40 sprayed directly on the teeth or on the material, but it has to be removed if you're going to weld the cut joint.

Clamping:It's also a good idea to clamp your work to the fence if you're using a miter saw. You don't want the stock - even light extrusions - to move or shift while you're cutting it. And please don't try to cut more than one piece at a time! I had one customer destroy a brand-new blade doing that, when one piece moved slightly and the impact knocked half the tips right off. He thought he was saving time by cutting three at a time, holding them with one hand. An expensive mistake!

"We're moving from MIG welding of steel to MIG welding of aluminum, but we keep having problems with feedability. I know Schupan has extensive experience with aluminum welding. Any suggestions?"

I checked in with Tommy, our lead welder. Here's what he says:

"Feedability is a bigger issue with aluminum than steel. This is due to the difference between the materials' mechanical properties. Steel welding wire is rigged, can be fed more easily over a longer distance and can withstand far more mechanical abuse when compared to aluminum. Aluminum is softer, and more susceptible to being deformed or shaved during the feeding operation. Make sure you pay close attention when selecting and setting up a feeding system for MIG welding. Look at your braking system tension, drive rolls, and contact tip ID. Let us know how it works out."

"Do you have any advice for someone new at cutting plastics? I am making straight cuts in 3-4 mm ABS plastic but I'm finding that it's much different than cutting metals. Will laser cutters leave a clean edge without melting/distorting? What power laser cutter should I be looking at for this application?"

Dave is our go-to plastics cutting guy. Here's his advice:

"Laser cutting ABS may leave a slight radius on the front side. If you need a nice sharp edge you may want to reverse cut. Unlike Acrylic which vaporizes, ABS melts and decomposes, but this is not to say the finish won't be acceptable. The other slight difference is that depending on lens focal length the edge may be slightly angled, but on 3-4mm you won't notice."

"We're looking for telescoping tubing. Does Schupan have it in stock?"

We don't stock telescoping tubing in-house, but we can supply telescoping tubing on a contract basis if your quantities are in the range of 3000-5000 pieces. If you're looking for smaller quantities, several of our partners may be able to help you, depending on your specifications. Call us for a reliable referral, at 1-800-724-8718.